As a start, here is a couple of ways to read a file with javascript

HttpRequest: (from web server or absolute path)

Source: Javascript - read local text file

function readTextFile(file)

{

    var rawFile = new XMLHttpRequest();

    rawFile.open(GET, file, true);

    rawFile.onreadystatechange = function ()

    {

        if(rawFile.readyState === 4)

        {

            if(rawFile.status === 200 || rawFile.status == 0)

            {

                var allText = rawFile.responseText;

                alert(allText);

            }

        }

    }

    rawFile.send(null);

}

And specify file:// in your filename when using an absolute path

readTextFile(file:///C:/your/path/to/file.txt);

FileReader API:

Source:

- http://codepen.io/matt-west/pen/KjEHg

- http://blog.teamtreehouse.com/reading-files-using-the-html5-filereader-api

HTML

<div id=page-wrapper>



    <h1>Text File Reader</h1>

    <div>

        Select a text file: 

        <input type=file id=fileInput>

    </div>

    <pre id=fileDisplayArea><pre>



</div>

JS

window.onload = function() {

    var fileInput = document.getElementById('fileInput');

    var fileDisplayArea = document.getElementById('fileDisplayArea');



    fileInput.addEventListener('change', function(e) {

        var file = fileInput.files[0];

        var textType = /text.*/;



        if (file.type.match(textType)) {

            var reader = new FileReader();



            reader.onload = function(e) {

                fileDisplayArea.innerText = reader.result;

            }



            reader.readAsText(file);    

        } else {

            fileDisplayArea.innerText = File not supported!

        }

    });

}

JS on MS Windows (simple sample)

Source: http://msdn.microsoft.com/en-us/library/czxefwt8(v=vs.84).aspx

function ReadFiles()

{

   var fso, f1, ts, s;

   var ForReading = 1;

   fso = new ActiveXObject(Scripting.FileSystemObject);

   ts = fso.OpenTextFile(c:\testfile.txt, ForReading);

   s = ts.ReadLine();

   // s holds the text content

   ts.Close();

}